Superplastic aluminum-based alloy material and production process thereof

Abstract

A superplastic aluminum-based alloy material consisting of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of the main alloying element (i.e., the matrix element) and the other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, the particles having a mean particle size of 0.001 to 0.1 μm. The superplastic aluminum-based alloy material is produced from a rapidly solidified material consisting of an amorphous phase, a microcrystalline phase or a mixed phase thereof by optionally heat treating at a prescribed temperature for a prescribed period of time and then subjecting to a single or combined thermo-mechanical treatment. The superplastic aluminum-based alloy material of the present invention is suited for to superplastic working.

What is claimed is: 
     
       1. A process for producing a superplastic aluminum-based alloy which exhibits a large elongation at high strain rates of 10 -1  s -1  or larger, the process comprising: forming an aluminum-based alloy consisting of an amorphous phase, a microcrystalline phase or a mixed phase thereof by rapidly quenching an alloy having a particular composition, said particular composition being represented by the general formula: Al a  M 1 (b-d) M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, d and e are, in atomic percentages, 75≦a≦97, 0.5≦b≦15, 0.5≦d≦5 and 0.5≦e≦10;   optionally, heat treating the aluminum-based alloy; and   subjecting the aluminum-based alloy to a single or combined thermo-mechanical treatment to provide an alloy having a microstructure suitable for superplastic working, in which said microstructure consists of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm.   
     
     
       2. The process for producing the superplastic aluminum-based alloy of claim 1, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       3. The process for producing the superplastic aluminum-based alloy of claim 1, wherein the superplastic aluminum-based alloy is suitable for high speed working. 
     
     
       4. A process for producing a superplastic aluminum-based alloy exhibiting a large elongation at high strain rates of 10 -1  s -1  or larger, the process comprising: forming an aluminum-based alloy consisting of an amorphous phase or a mixed phase of an amorphous phase and a microcrystalline phase by rapidly quenching an alloy having a particular composition, said particular composition being represented by the general formula: Al a  M 1 (b-d) M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, d and e are, in atomic percentages, 75≦a≦97, 0.5≦b≦15, 0.5≦d≦5 and 0.5≦e≦10;   heat treating the aluminum-based alloy at the crystallization temperature, Tx, +100°±50° C. for 0.5 to 5 hours; and   subjecting the aluminum-based alloy to a single or combined thermo-mechanical treatment at the crystallization temperature, Tx, ±150° C. for 0.1 to 1 hour to provide an alloy having a microstructure suitable for superplastic molding, in which said microstructure consists of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm.   
     
     
       5. The process for producing the superplastic aluminum-based alloy of claim 4, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       6. The process for producing the superplastic aluminum-based alloy of claim 4, wherein the superplastic aluminum-based alloy is suitable for high speed working. 
     
     
       7. A process for producing a superplastic aluminum-based alloy which exhibits a large elongation at high strain rates of 10 -1  s -1  or larger, the process comprising: forming an aluminum-based alloy consisting of an amorphous phase, a microcrystalline phase or a mixed phase thereof by rapidly quenching an alloy having a particular composition, said particular composition being represented by the general formula: Al a  M 1 (b-c-d) M 2c  M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 2  is at least one element selected from the group consisting of V, Cr and W; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, c, d and e are, in atomic percentages, 75≦a≦97, 0.523 b≦15, 0.1≦c≦5, 0.5≦d≦5 and 0.5≦e≦10;   optionally, heat treating the aluminum-based alloy; and   subjecting the aluminum-based alloy to a single or combined thermo-mechanical treatment to provide an alloy having a microstructure suitable for superplastic working, in which said microstructure consists of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm.   
     
     
       8. The process for producing the superplastic aluminum-based alloy of claim 7, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       9. The process for producing the superplastic aluminum-based alloy of claim 7, wherein the superplastic aluminum-based alloy is suitable for high speed working. 
     
     
       10. A process for producing a superplastic aluminum-based alloy exhibiting a large elongation at high strain rates of 10 -1  s -1  or larger, the process comprising: forming an aluminum-based alloy consisting of an amorphous phase or a mixed phase of an amorphous phase and a microcrystalline phase by rapidly quenching an alloy having a particular composition, said particular composition being represented by the general formula: Al a  M 1 (b-c-d) M 2c  M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 2  is at least one element selected from the group consisting of V, Cr and W; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, c, d and e are, in atomic percentages, 75≦a≦97, 0.5≦b≦15, 0.1≦c≦5, 0.5≦d≦5 and 0.5≦e≦10;   heat treating the aluminum-based alloy at the crystallization temperature, Tx, +100°±50° C. for 0.5 to 5 hours; and   subjecting the aluminum-based alloy to a single or combined thermo-mechanical treatment at the crystallization temperature, Tx, ±150° C. for 0.1 to 1 hour to provide an alloy having a microstructure suitable for superplastic molding, in which said microstructure consists of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm.   
     
     
       11. The process for producing the superplastic aluminum-based alloy of claim 10, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       12. The process for producing the superplastic aluminum-based alloy of claim 10, wherein the superplastic aluminum-based alloy is suitable for high speed working. 
     
     
       13. A superplastic aluminum-based alloy consisting of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm and said superplastic aluminum-based alloy exhibiting a large elongation at high strain rates of 10 -1  s -1  or larger and consisting of a composition represented by the general formula: Al a  M 1 (b-d) M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, d and e are, in atomic percentages, 75≦a≦97, 0.5≦b≦15, 0.5≦d≦5 and 0.5≦e≦10. 
     
     
       14. The superplastic aluminum-based alloy of claim 13, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       15. The superplastic aluminum-based alloy of claim 13, wherein the superplastic aluminum-based alloy is suitable for high speed working. 
     
     
       16. A superplastic aluminum-based alloy consisting of a matrix formed of aluminum or a supersaturated aluminum solid solution, whose average crystal grain size is 0.005 to 1 μm, and particles made of a stable or metastable phase of various intermetallic compounds formed of a main alloying element making up the matrix and other alloying elements and/or of various intermetallic compounds formed of the other alloying elements and distributed evenly in the matrix, said particles having a mean particle size of 0.001 to 0.1 μm and said superplastic aluminum-based alloy exhibiting a large elongation at high strain rates of 10 -1  s -1  or larger and consisting of a composition represented by the general formula: Al a  M 1 (b-c-d) M 2c  M 3d  X e , wherein M 1  is at least one element selected from the group consisting of Mn, Fe, Co, Ni and Mo; M 2  is at least one element selected from the group consisting of V, Cr and W; M 3  is at least one element selected from the group consisting of Li, Ca, Mg, Si, Cu and Zn; X is at least one element selected from the group consisting of Nb, Hf, Ta, Y, Zr, Ti, rare earth elements and a mixture of rare earth elements; and a, b, c, d and e are, in atomic percentages, 75≦a≦97, 0.5≦b≦15, 0.1≦c≦5, 0.5≦d≦5 and 0.5≦e≦10. 
     
     
       17. The superplastic aluminum-based alloy of claim 16, wherein the superplastic aluminum-based alloy exhibits a large elongation at a strain rate of 10 -1  s -1  at a temperature of at least 400° C. 
     
     
       18. The superplastic aluminum-based alloy of claim 16, wherein the superplastic aluminum-based alloy is suitable for high speed working.